PREVENTION, KICK-BACK.--A choke coil placed in the power circuit to prevent the high frequency currents from getting into the transformer and breaking down the insulation.

Q S T.--An abbreviation used in wireless communication for (1) the question "Have you received the general call?" and (2) the notice, "General call to all stations."

QUENCHED GAP.--See Gap, Quenched.

RADIATION.--The emission, or throwing off, of electric waves by an aerial wire system.

RADIO AMMETER.--See Ammeter, Hot Wire.

RADIO FREQUENCY.--See Frequency, Radio.

RADIO FREQUENCY AMPLIFICATION.--See Amplification, Radio Frequency.

RADIO FREQUENCY CURRENT.--See Current, Radio Frequency.

RADIO INSPECTOR.--See Inspector, Radio.

RADIOTRON.--The trade name of vacuum tube detectors, amplifiers, oscillators and modulators made by the Radio Corporation of America.